ETOPS, while it is usually applied to overwater flights, applies to flights more than 60 minutes from a suitable airport. A flight from from Sydney to Perth can be an ETOPS flight if the route of flight takes the aircraft more than 60 minutes from a suitable airport.

This may be a bit off topic but since we are talking ETOPS.... I just found out -nope, the discovery is not mine- that Boeing subsidizes an airport in the Pacific (Midway -MDY) so that it provides an alternate airport for airlines flying under ETOPS rule... Now, that is a good investment for Boeing, isn't it.....